Baculites sp.

KENNEDY, W. J., LANDMAN, N. H., COBBAN, W. A. & JOHNSON, R. O., 2000, Additions to the Ammonite Fauna of the Upper Cretaceous Navesink Formation of New Jersey, American Museum Novitates 3306, pp. 1-31 : 16

Baculites sp.

Figure 7A–F

DESCRIPTION: NJSM 12931 (fig. 7D–F) is 44 mm long with an oval whorl section 16.0 mm high and 12.5 mm wide at its larger end. The taper angle of the shell is 3°. The only ornament is very weak, closely spaced ventral ribbing. The simple suture is poorly preserved. NJSM 13439 (fig. 7A–C) is a body chamber fragment 37 mm long with an oval whorl section 17.6 mm high and 13.1 mm wide in the middle of the specimen. Lirae are concave on the dorsal third of the flanks and project strongly forward on the ventral twothirds of the flanks. The lirae strengthen into ribs and cross the venter with a narrow convexity.

NJSM GP 14257 (not illustrated) is a fragment 29 mm long, with an oval whorl section, 13.5 mm high and 9.3 mm wide at its larger end. The venter is very narrow and slightly pinched. The taper angle of the shell is 3°. Ornament is lacking, except for weak ventral ribs that have a rib index of 3. The incompletely preserved suture is simple, as for the genus.

DISCUSSION: In their small size, oval whorl section, narrow venter, and smooth flanks, these specimens resemble material from the Maastrichtian Prairie Bluff Chalk of Mississippi described as species A and C by Cobban and Kennedy (1995).

OCCURRENCE: Navesink Formation, Inversand Pit and along the bank of Chestnut Branch Creek , Sewell, Gloucester County, New Jersey (for details of this locality, see Richards, 1956: 79; Gallagher, 1984: 26; 1992; 1993: 142) .

Figures

Fig. 7. A–F. Baculites sp. A–C. NJSM 13439; D–F. NJSM 12931. Both specimens are from the Navesink Formation, Inversand Pit, Sewell, Gloucester County, New Jersey. G–I. Nostoceras (Nostoceras) hyatti Stephenson, 1941, MAPS A2004a3, pathological macroconch with only one row of ventral tubercles, lower phosphatic layer, Navesink Formation, Atlantic Highlands, New Jersey. All figures are X1.